This invention is related to the field of telephony. It introduces a new way of transferring audio and image data concurrently through a narrow bandwidth telephony system like PSTN. It discloses the idea of real-time transmission of speech concurrently with a non real-time transmission of quality images over a single physical telephone line.
Nowadays audio and video communication systems are based on the Internet, an intranet, or ISDN, etc. as these audio and video communication systems may require a bandwidth higher than that can be provided by a traditional POTS. Two types of audio and video communication systems are briefly discussed below:
A videophone system requires both audio and video information be simultaneously transferred via a network in real time. Thus, inherently, the videophone system requires a high bandwidth network such as an ISDN for support. For those skilled in the art, the H.320 and H.323 standard describe the implementation of such a videophone system. An example of a commercial videophone system is Polycom""s VS4000 videoconferencing system. While it provides for a simultaneous transfer of audio and video information between its users, the videophone system has the following disadvantages:
1. It is very expensive as both communication sites need to have a set of expensive video and audio equipments.
2. It needs to have a wide bandwidth connection, such as ISDN, for the transfer of video information.
3. It may still need an extra phone line to transfer an accompanying audio information.
4. If the system is implemented completely on a single wide bandwidth connection then it may not be compatible with the existing telephone system.
Another type of audio and video communication system are tele-conference systems. These systems are PC based and the connection is most likely through the Internet via a PC modem. Upon the establishment of a connection, the peer parts can exchange audio, video, data or any other kinds of information. An example of a commercial tele-conference system is Microsoft""s NetMeeting. While it is not as expensive as the video phone system, the tele-conference system still has the following disadvantages:
1. It is still expensive as both communication sites still need a PC with an attached audio device and possibly also an attached video device.
2. Both sites still need to have some kind of Internet or intranet connection, via a Cable Modem, an ISDN or a dial-in modem, etc.
3. If the connection involves Internet, the audio quality could be bad depending upon the condition of the Internet traffic.
4. It is not compatible with the existing telephone system thus no normal phone conversation can take place.
In essence, both of these audio and video communication systems are incapable of concurrently transferring both audio and image information over a narrow bandwidth PSTN efficiently with a low-cost device while maintaining compatibility with the current standard telephone line. Therefore, the present invention of an Image Transceiving Telephone with Integrated Digital Camera (ITTDC) is disclosed to solve the aforementioned problems as well as to transfer high quality images over any long distance connection through the ubiquitous standard phone line.
The ITTDC is invented to simultaneously transfer speech audio and image (including still and multi-frames) information over the same standard telephone line without the need of any expensive equipment. As a matter of course, both the audio and image information have to be digitized and compressed before transmission to make the most use of a single telephone line. However, during the transfer process, audio information is given a highest priority hence it is transferred in real time. On the other hand, image information is given a lower priority hence it is transferred on a non real-time basis generally not in synchrony with the audio information. Basically, the ITTDC is an enhanced telephone comprising three major modules: a digital camera, a telephone (MIC plus speaker) and a modem. The telephone module is made compatible with current standard telephone hence it can make and answer ordinary phone calls with any existing telephone unit of the world. In addition, the ITTDC is equipped with capability to make advanced phone calls to a peer system of another similarly equipped ITTDC. For example, the ITTDC provides for a local image storage and preview whereby a user of the ITTDC can capture an image and preview it before sending the image to a remote peer system. Likewise, the user can save, in a local storage, an image transferred from a remote peer system for later review. With properly integrated software for accessing an ISP, the ITTDC can exchange locally stored images as well as audio clips with an ISP server or with stored images as well as audio clips on a remote peer system connected to the Internet. Accordingly, it can free up its local storage, making itself even more powerful. When the downloaded audio clips are MP3 files, the CCITT can function as an MP3 player. The ITTDC can also function as an enhanced telephone answering machine with accompanying audios and images.
An object of the present invention is to have the ITTDC simultaneously transfer audio and image information over a ubiquitous standard telephone line without the need of any expensive equipment. In essence, the ITTDC would transfer the audio information in real-time while transferring the image information with quality on a non real-time basis.
Another object is for the ITTDC to function essentially as a digital camera with an added audio input/output device and a modem. Thus, the ITTDC can provide the complete capability of a standard digital camera with an additional ability to exchange images with a peer ITTDC or an ISP server.
A third object of the present invention is to have the ITTDC capable of making a phone call to another user of a traditional telephone and carrying on a real-time conversation with the other user.